[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TCML] static gap singing coil hybrid.



John,
     I'll keep an eye open for some graphite, I have a graphite
crucible but as I'm still having fun making bronze with it I'm not
ready to delegate it for TC duty...  In any event what exactly do you
mean "squares of carbon?"  Is this something you buy, or is it the
stuff you put in your grill to cook cheeseburgers, or something else?
Thanks.

Scott Bogard.

On 1/27/11, jhowson4@xxxxxxxxxxx <jhowson4@xxxxxxxxxxx> wrote:
> If you need a beefy resistor...
>
> Try stacking squares of carbon and just tapping the ends in a vice. graphite
> might work as well
> You get a variable resistor where a fixed metal plate and a movable one
> serve as the terminals ; the resistance value is reduced by applying
> pressure to the movable plate.
>
> I have no idea what the effective resistance range that can be achieved
> would be, but I know that these guys can handle hundreds of amps no problem
> a lot lighter than a salt water resistor as well =)
>
>
> Thanks,
> John "Jay" Howson IV
>
>
> "Why thank you, I will be happy to take those electrons off you hands."
>
>
> ----- Original Message -----
> From: "Scott Bogard" <sdbogard@xxxxxxxxx>
> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> Sent: Wednesday, January 26, 2011 10:14:27 PM
> Subject: Re: [TCML] static gap singing coil hybrid.
>
> Oh yes, that makes sense... If I get impatient I'll probably just make
> a resistor out of a bucket of salt water and some metal plates, very
> inefficient and short lived but I imagine it will prevent inrush to the
> gap and still allow the tank cap to charge. It will be some time before
> I build a prototype as I have no idea how to interface with midi, though
> I suppose I could rig a 555 timer with about 4% duty cycle at 30Hz-5khz
> to trigger another driving a flyback at 100 kHz to be my trigger, that
> way I can get at least steady sound, pitch adjustable with a
> potentiometer as proof of concept, and not worry about midi until later.
>
> Scott Bogard.
>
> On 1/25/2011 9:33 PM, Phillip Slawinski wrote:
>> Scott,
>>
>> The MOTs will probably work. Also the charging inductor serves the purpose
>>
>> of limiting the current from the filter capacitors when the spark gap is
>> triggered. Remove the inductor, and you end up dumping the the filter
>> capacitors across the spark gap when it's triggered.
>>
>> -Phillip
>>
>> On Tue, Jan 25, 2011 at 17:55, Scott Bogard<sdbogard@xxxxxxxxx> wrote:
>>
>>> Phillip,
>>> I was planning on eventually building a DC coil eventually anyway,
>>> and I have enough microwave oven capacitors and diodes that I could build
>>> a
>>> MOT based level shifter with all the current I can handle, not sure if
>>> that
>>> would cut it or if I would need a resonate charging inductor, which could
>>> be
>>> made with more MOTs in theory. Since it is triggered it shouldn't need an
>>>
>>> especially high voltage I suppose, so 4kV was where I was aiming. The
>>> biggest hurtle I see is cooling, having that arc that close to glass for
>>> prolonged periods will be tricky, but maybe if I run cold air or oil or
>>> even
>>> water through the tube, its life expectancy should be similar to glass
>>> jar
>>> capacitors I'd imagine, even if I only get 15 minutes out of it glass
>>> tubing
>>> is a lot cheaper than IGBT's, and is easy to replace...
>>>
>>> Scott.
>>>
>>>
>>> On 1/25/2011 1:13 PM, Phillip Slawinski wrote:
>>>
>>>> Scott,
>>>>
>>>> While this looks okay in theory, there would be some limitations. The
>>>> main
>>>> limitation would be that this could only work with a DC charging system.
>>>>
>>>> This adds complexity to the project, because you must then locate large
>>>> HV
>>>> filter caps, diodes, and a properly designed charging reactor. Aside
>>>> from
>>>> those issues, I don't see any fundamental reasons why it can't be done.
>>>> If
>>>> you do this please share your results.
>>>>
>>>> -Phillip
>>>>
>>>> On Tue, Jan 25, 2011 at 11:44, Scott Bogard<sdbogard@xxxxxxxxx> wrote:
>>>>
>>>> Greetings all,
>>>>> So I was looking at this web page today at work for no particular
>>>>> reason...
>>>>> http://www.glacialwanderer.com/hobbyrobotics/
>>>>> If I am understanding this correctly, he essentially built a spark gap
>>>>> triggered by the corona around the inner glass tube from his trigger
>>>>> coil. If that is correct would it be terribly easy (if extremely
>>>>> inefficient) to make a singing coil by constructing a similar spark
>>>>> gap (with better cooling for actual run times) and just trigger the
>>>>> inner coil with a midi signal. This way for those of us who don't
>>>>> want to tackle DRSSTC yet, can just build essentially a midi triggered
>>>>> flyback, to gain familiarity with the audio interfacing without the
>>>>> added complication of going strictly solid state, and the expense of
>>>>> IGBTs. Has anyone tried this?
>>>>>
>>>>> Scott.
>>>>> _______________________________________________
>>>>> Tesla mailing list
>>>>> Tesla@xxxxxxxxxx
>>>>> http://www.pupman.com/mailman/listinfo/tesla
>>>>>
>>>>> _______________________________________________
>>>> Tesla mailing list
>>>> Tesla@xxxxxxxxxx
>>>> http://www.pupman.com/mailman/listinfo/tesla
>>>>
>>>> _______________________________________________
>>> Tesla mailing list
>>> Tesla@xxxxxxxxxx
>>> http://www.pupman.com/mailman/listinfo/tesla
>>>
>> _______________________________________________
>> Tesla mailing list
>> Tesla@xxxxxxxxxx
>> http://www.pupman.com/mailman/listinfo/tesla
>>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla